Colloidal quantum dots (CQDs) exhibit efficient photoluminescence with widely tunable bandgaps, owing to quantum confinement effects. They are emerging as an appealing complement to epitaxial semiconductor laser materials which are ubiquitous and technologically mature, but unable to cover the full visible spectrum (red, green, and blue-RGB). However, the requirement of high CQD packing density and the complication by nonradiative multi-excitonic Auger recombination have been obstacles for advancing colloidal CQD laser development.